ACT leader David Seymour says his proposed free speech protections would not allow people to spread footage of the Christchurch terror attack.
Philip Arps - a Christchurch business owner and self-proclaimed neo-Nazi - was yesterday sentenced to 21 months in prison for sharing a video of the massacre in which 51 people were killed.
He also asked an unknown person to add cross-hairs and a body count to the video to "make it more fun". Arps is appealing the prison sentence.
The 44-year-old earlier pleaded guilty to two charges of distributing objectionable material under the Films, Videos, and Publications Classification Act.
Mr Seymour said ACT's recently announced free speech policy would not and should not prevent a person like Arps from being charged.
"In the case of this guy in Christchurch, his real crime in my view was that he was actually inciting people ... or glorifying people undertaking violent acts, and that is a crime quite separate from anything else," Mr Seymour told RNZ.
"Freedom of speech does not cover threatening or inciting violence, or criminal nuisance. It never has and it never should, because those things are truly dangerous."
Under its "Freedom to Speak" policy, the ACT Party would repeal parts of the Human Rights Act and the Summary Offences Act which make insulting and offensive speech unlawful. It would also restrict the Harmful Digital Communications Act to complainants under the age of 18.
But Mr Seymour said he would leave the Films, Videos, and Publications Classification Act unchanged as it existed "primarily to protect children".
"We haven't seen it as a major problem. It doesn't seem to be the area where people are most often persecuted."
The policy, however, would remove the "offensive behaviour" charge under which Arps was reportedly found guilty in 2016.
In that case, Arps filmed himself performing Hitler salutes and dumping a box of pigs' heads outside the Masjid Al-Noor mosque in Christchurch.
Mr Seymour said that behaviour is "absolutely reprehensible", but should not be a crime in itself.
"Once you make it a crime, you can imagine other people - such as the kinds of activities that Greenpeace get up to - being seen as similarly reprehensible or nuisance-like. The only difference is whether or not they're politically acceptable.
"The issue is not whether or not people should be allowed to do something. The issue is: what can we trust the state to moderate?"
Mr Seymour suggested Arps may have been able to be charged with other offences in the 2016 case, such as trespassing or being a nuisance.
"We should have a paradigm where you can say what you like so long as you do not threaten or incite violence, or commit other crimes along the way as some of these less desirable people often do."